pds-bridge/flake.nix

{
  description = "Example Rust development environment for Zero to Nix";

  # Flake inputs
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.05";
    rust-overlay.url = "github:oxalica/rust-overlay"; # A helper for Rust + Nix
  };

  # Flake outputs
  outputs = { self, nixpkgs, rust-overlay }:
    let
      pdsDirectory = "/home/pan/prog/atproto/authlink";

      # Overlays enable you to customize the Nixpkgs attribute set
      overlays = [
        # Makes a `rust-bin` attribute available in Nixpkgs
        (import rust-overlay)
        # Provides a `rustToolchain` attribute for Nixpkgs that we can use to
        # create a Rust environment
        (self: super: {
          rustToolchain = super.rust-bin.stable.latest.default;
        })
      ];

      # Systems supported
      allSystems = [
        "x86_64-linux" # 64-bit Intel/AMD Linux
        "aarch64-linux" # 64-bit ARM Linux
        "x86_64-darwin" # 64-bit Intel macOS
        "aarch64-darwin" # 64-bit ARM macOS
      ];

      # Helper to provide system-specific attributes
      forAllSystems = f: nixpkgs.lib.genAttrs allSystems (system: f {
        pkgs = import nixpkgs { inherit overlays system; };
      });

      # Systemd service configuration
      createSystemdService = pkgs: pdsDir: pkgs.writeTextFile {
        name = "pds.service";
        text = ''
          [Unit]
          Description=Development Environment Service
          After=network-online.target
          Wants=network-online.target

          [Service]
          Type=simple
          ExecStart=${pkgs.pds}/bin/pds
          WorkingDirectory=${pdsDir}
          EnvironmentFile=${pdsDir}/.env
          Environment=PDS_DATA_DIRECTORY=${pdsDir}/.pds-data
          Environment=PDS_BLOBSTORE_DISK_LOCATION=${pdsDir}/.pds-data/blocks

          [Install]
          WantedBy=multi-user.target
        '';
      };

      # Scripts for managing the systemd service
      createServiceScripts = pkgs: pdsDir: 
        let
          serviceFile = createSystemdService pkgs pdsDir;
          serviceName = "pds";
        in {
          startScript = pkgs.writeShellScript "start-dev-service" ''
            set -e

            # Create user systemd directory if it doesn't exist
            mkdir -p ~/.config/systemd/user

            # Copy service file
            cp -f ${serviceFile} ~/.config/systemd/user/${serviceName}.service

            # Reload systemd and start service
            systemctl --user daemon-reload
            systemctl --user start ${serviceName}
            systemctl --user enable ${serviceName}

            systemctl --user status ${serviceName} --no-pager
          '';

          stopScript = pkgs.writeShellScript "stop-dev-service" ''
            set -e
            if systemctl --user is-enabled --quiet ${serviceName}; then
              # Stop and disable service
              systemctl --user stop ${serviceName} || true
              systemctl --user disable ${serviceName} || true

              # Remove service file
              rm -f ~/.config/systemd/user/${serviceName}.service

              # Reload systemd
              systemctl --user daemon-reload
            fi
          '';
        };
    in
    {
      # Development environment output
      devShells = forAllSystems ({ pkgs }:
        let
          scripts = createServiceScripts pkgs pdsDirectory;
        in {
          default = pkgs.mkShell {
            # The Nix packages provided in the environment
            packages = (with pkgs; [
              systemd
              # The package provided by our custom overlay. Includes cargo, Clippy, cargo-fmt,
              # rustdoc, rustfmt, and other tools.
              sqlx-cli
              rustToolchain
            ]) ++ pkgs.lib.optionals pkgs.stdenv.isDarwin (with pkgs; [ libiconv ]);

            # Only run systemd commands on Linux
            shellHook = pkgs.lib.optionalString pkgs.stdenv.isLinux ''
              # Cleanup
              ${scripts.stopScript}

              # Start the systemd service
              ${scripts.startScript}
            '';
          };
        });
    };
}